Improvement in friction-primers for cannon



W. BALL.

Gun Primer.

Patented March 1552.

IINTTED STATES PATENT OFFICE.

WILLIAM BALL, OF UBIOOIEE, MASSAOIIUSETI'S.

IMPROVEMENT IN FRICTION-PRIMERS FOR CANNON.

Specification forming part of Letters Patent No. 8,820, dated March 23, 1852.

To all whom it may concern:

Be it known that I, WILLTAM BALL, of Chicopee, in the county of Hampden and State of Massachusetts, haveinvented an Improvement in Friction-Primers for Cannon or Ordnance; and I do herebydeclare the natureof my invention and the manner in which the same is made or compounded to be fully set forth and de scribed in the following specification, accompanying drawings, and letters, figures, and references marked thereon.

The friction primers heretofore in common use have generally consisted of a small tube partially filled with gunpowder and having a plugofsand-paper inserted in one end, through the center of which plug a string was passed whose end within the tube had been previously or was afterward coated with a composition of phosphorus and various other matters, which composition would take tire by friction when the string was pulled out ofthe tube, thereby setting fire to the charge of gunpowder. The phosphoric composition, being surrounded by the gunpowder, soon absorbs oxygen, and in consequence thereof phosphoric acid is produced, which notonly destroys the composition on the string and renders it inexplosive, but it acts on the gunpowder and produces such a change in it as to materially inj ureit. Besides, the manner in which the strings are inserted and held in the tube renders them, when pulled by an artilleryman, very liable to be cut or broken oft'. 'lhese defects in the construction of friction-primers I have endeavored to remedy in that which I shall now proceed to describe.

Figure 1 of the aforementioned drawings denotes a View of one of my improved primers, and Fig.2 isa central and longitudinal section of the same.

In its external appearance itdoes not differ essentially from the common primers above alluded to, but in its internal arrangement it is somewhat varied therefrom. Like them it is made of a tube, a, of paper or other suitable material, and a discharging-string, b, inserted therein. The said string ispassed and partially drawn through asmallcylindrical piece of thick and hard leather or rawhide, c, which is inserted and connected or confined in one end of the tube, the end of the string being drawn entirely through, so as to project about one-half the length of the tube beyond the open end thereof. This done, a piece or strip of sandpaper having a small quantity of a priming composition (made offulminating-mercury and detonating-silver in theproportion of tive parts of the former to one ofthe latter) sprinkled upon or near one end of it is rolled upon the string between the open mouth of the tube and the end of the string immediately adjacent thereto. The piece of sandpaper should bein its width about one-third the length of the tube, and it should have the priming composition laid along its edge where it first comes in contact with the string, and when rolled on the string the lower end of the latter should project beyond its lower end about one quarter of an inch. When the priming is laid upon the paper it should be moistened or wet with alcohol, in or der to prevent explosion from accident. In order to insure the explosion of the priming by friction of the string, the end of the latter, which projects the short distance of a quarter of an inch beyond the rollof sand-paper, should be dipped in shellac varnish and before the latter is dry the part so dipped should have powdered emery or sand sprinkled upon it, or it should be plunged in emery or sand, for the purpose of forming thereon a pellet or knob, c, which shall have a rough or sharp scratchingsurface. The string isthen drawn through the leather cylinder or plug c in such a manner as to carry the roll of sandpaper into the interior of the tube and against the lower end of the plug, as seen at d in Fig.2. The charge or load j' of the primer (made of twenty-four parts of chlorate of potash, seven of sulphur, four of gunpowder, and two oferude antimony) is next introduced into the tube, so as to nearlyfill the space below the sand-paper and to rest in contact with the paper and pellet or knobe of the string. This done, the extreme end ofthe tube should be sealed up, as at h, with a little gumshellac or some drying composition which will be suitable to protect the charge from the absorption of moisture. The exterior surface of the primer being next varnished over, and a loop, g, made at the end of the string, as seen in the drawings, the primer is completed and ready to be used. When used the tube of the primer is inserted in the vent-hole of the cannon and the charge of it is exploded by a person standing by the side of the cannon and pulling the string horizontally or obliquely (not vertically) by means of a hook inserted in the loop or the string.

The cylinder of leather acts as a kind ot' breech to canse the charge to explode downward with force, and being a soft or yielding substance in comparison with wood or metal, it prevents the string from being eut oi when pulled at right angles. It does away with the little lock or pulley xture in common use for the string to pass over, and which generally costs about three dollars, and is indispensable to the friction-primers as ordinarily made and used.

Thefulminating-niercnry in comparison with detonating-silver is slow of action when tired, and requires much friction to explode it. The detonating-silver is very expensive, but its coinbination with the fulminatiiig-mercury renders but little friction necessary to fire the mercury, as the silvel` requires but; a slight friction to ignite it, and when ignited it communicates tire to the mercury, which in its turn explodes the charge. The priming compound ot' fulminating-mercnry and detonating-silver will not set fire with certainty to gunpowder, but it will set fire with certainty to the charge composed ofthe ingredients as above described.

I claim- The combining with the discharging-string and tube ofthe primer a cylinder or plug of leather, c, or other like substance inserted and secured in the upper end of the primer and having the exploding-string passing through it, as above set forth, the said plug or cylinder serving the purpose of a breech to confine the charge when exploded, as a protector of the sand-paper and priming againstthe absorption of humidity, and as a bearing for the string to draw over when pulled.

In testimony whereof I have hereto set my signature this 3d day of November, A. D.1851.

WM. BALL.

Witnesses:

PHILANDER H. STREET, WM. WHEELER. 

